LONDON, Sun Jul 27, (bdnews24.com/Reuters) - Bosnia is closer to breaking up than at any time since its 1992-95 war and the European Union must do more to prevent its division, former international peace overseer Paddy Ashdown said.

Ashdown said the Serb Republic, which together with the Muslim-Croat federation makes up the Bosnian state, had set up parallel institutions and was working towards secession.

"Radovan Karadzic is at last on his way to The Hague. But the division of Bosnia that was his dream is now more likely than at any time since he became a fugitive," Ashdown said in an article published by The Observer newspaper on Sunday.

Karadzic, leader of the Bosnian Serbs in the Bosnia war, was arrested in Serbia this week after 11 years in hiding.

The Muslim-Croat federation and the Serb Republic have run separate police forces in Bosnia since hostilities ended.

In April Bosnia's parliament approved a law which intended to unify the forces, but after four years of debate the original plan was watered down and the merger will be largely cosmetic.

Ashdown said Milorad Dodik, prime minister of the Serb Republic "is now aggressively reversing a decade of reforms" and had used the autonomy granted by the Dayton peace accords which ended Bosnia's war "to undermine the Bosnia Dayton envisaged".

The European Union should use Bosnia's EU membership aspirations as a lever to push for reforms which would support Bosnian central government, said Ashdown, who served as High Representative in Bosnia from 2002 to 2006..

"Brussels must ... resist attempts to undermine the Bosnian state, insist on constitutional reform to make Bosnia more functional and tackle corruption which is becoming ever more embedded," he wrote.

It should also tell neighboring Serbia that a key condition for progress in its own efforts towards EU membership "will be to support the Bosnian state and give no succor to those who seek to undermine it".